Partial discharges and noise separation in high frequency signals using inductive sensors

Partial discharges in high voltage equipment are a cause and consequence of premature ageing. Thus, its accurate measurement is an important diagnosis tool trying to avoid premature failures. Classical phase resolved patterns are now completed with pulse waveform analysis in order to discriminate between PD sources and PD from noise. For this purpose, high frequency inductive sensors are being used in recent years. In this paper, a fixed post-processing technique for PD pulse waveforms will be used to discriminate between discharges from electrical noise for two inductive sensors: a commercial High Frequency Current Transformer and a newly developed inductive loop sensor. Results will prove that this novel inductive loop sensor is able to discriminate PD from electrical noise for several test objects.